Copyright © 2018 International Anesthesia Research Society. Unauthorized reproduction of this article is prohibited. XXX 2018 • Volume XXX • Number XXX www.anesthesia-analgesia.org 1 DOI: 10.1213/ANE.0000000000003554 O besity is a worldwide epidemic of previous unknown proportions challenging public health in high- and low-income countries alike. In 2016, the World Health Organization estimated that 39% of the adult population were overweight, defned by a body mass index (BMI) of ≥25 kg·m −2 , and 13% were obese (BMI, ≥30 KEY POINTS • Question: Obesity is a rapidly increasing threat to global health, recognized as a cardiovascu- lar risk factor; we investigated whether there are cardiac structural and functional differences between term healthy and obese parturients. • Finding: Morbidly obese pregnant women have signifcantly higher left ventricular mass and lower stroke volume index than pregnant women of normal body weight, and the basal inter- ventricular septum shows signs of remodeling as indicated by lower septal tissue Doppler velocities. • Meaning: These structural and functional cardiac differences could limit cardiovascular adap- tation of obese patients in obstetric emergency situations. BACKGROUND: The increasing prevalence of obesity worldwide is a major threat to global health. Cardiac structural and functional changes are well documented for obesity as well as for pregnancy, but there is limited literature on morbidly obese parturients. We hypothesized that there are both cardiac structural and functional differences between morbidly obese pregnant women and pregnant women of normal body mass index (BMI). METHODS: This prospective cross-sectional study was performed in 2 referral maternity units in Cape Town, South Africa, over a 3-month period. Forty morbidly obese pregnant women of BMI ≥40 kg·m −2 (group O) were compared to 45 pregnant women of BMI ≤30 kg·m −2 (group N). Cardiac structure and function were assessed by transthoracic echocardiography, according to the recommendations of the British Society of Echocardiography. The 2-sample t-test with unequal variances was used for the comparison of the mean values between the groups. RESULTS: Acceptable echocardiographic images were obtained in all obese women. Statistical signifcance was defned as P < .0225 after applying the Benjamini–Hochberg correction for multiple testing. Mean (standard deviation) mean arterial pressure was higher in group O (91 [8.42] vs 84 [9.49] mm Hg, P < .001). There were no between-group differences in heart rate, stroke volume, or cardiac index (84 [12] vs 79 [13] beats·minute −1 , P = .103; 64.4 [9.7] vs 59.5 [13.5] mL, P = .069; 2551 [474] vs 2729 [623] mL·minute −1 ·m −2 , P = .156, for groups O and N, respectively). Stroke volume index was lower, and left ventricular mass was higher in group O (30.14 [4.51] vs 34.25 [7.00] mL·m −2 , P = .003; 152 [24] vs 115 [29] g, P < .001). S′ septal was lower in group O (8.43 [1.20] vs 9.25 [1.64] cm·second −1 , P = .012). Considering diastolic function, isovolumetric relaxation time was signifcantly prolonged in group O (73 [15] vs 61 [15] milliseconds, P < .001). The septal tissue Doppler index E′ septal was lower in group O (9.08 [1.69] vs 11.28 [3.18], P < .001). There were no between-group differences in E′ average (10.7 [2.3] vs 12.0 [2.7], P = .018, O versus N) or E/E′ average (7.85 [1.77] vs 7.27 [1.68], P = .137, O versus N). Right ventricular E′/A′ was lower in group O (1.07 [0.47] vs 1.29 [0.32], P = .016). CONCLUSIONS: Cardiac index did not differ between obese pregnant women and those with normal BMI. Their increased left ventricular mass and lower stroke volume index could indicate a limited adaptive reserve. Obese women had minor decreases in septal left ventricular tissue Doppler velocity, but the E/E′ average values did not suggest clinically signifcant diastolic dys- function. (Anesth Analg XXX;XXX:00–00) Cardiac Structure and Function in Morbidly Obese Parturients: An Echocardiographic Study Bigna S. Buddeberg, MD,*† Nicole L. Fernandes, MBChB, DA (SA),* Adri Vorster, MBChB, FCA (SA),* Blanche J. Cupido, MBChB, MPhil, FCP (SA), Cert Cardio (SA),‡ Carl J. Lombard, MSc, PhD,§ Justiaan L. Swanevelder, MBChB, DA (SA), FCA (SA), MMed (Anaes), FRCA,* Thierry Girard, MD,† and Robert A. Dyer, MBChB, FCA (SA), PhD* From the *Department of Anaesthesia and Perioperative Medicine, University of Cape Town and Groote Schuur Hospital, Cape Town, South Africa; †Department of Anaesthesia, University Hospital Basel, Basel, Switzerland; ‡Department of Cardiology, University of Cape Town and Groote Schuur Hospital, Hatter Institute for Cardiovascular Research in Africa, Cape Town, South Africa; and §Biostatistics Unit, South African Medical Research Council, Cape Town, South Africa. Copyright © 2018 International Anesthesia Research Society Accepted for publication May 8, 2018. Funding: This work was funded by a travel grant given to the principal investigator by the Obstetric Anaesthetists’ Association. The authors declare no conficts of interest. Reprints will not be available from the authors. Address correspondence to Bigna S. Buddeberg, MD, University Hospital Basel, Spitalstrasse 21, Basel 4056, Switzerland. Address e-mail to bigna.bud- debergbichsel@usb.ch.